spore

Examples of spore in the following topics:

• Fungi Reproduction

  • Fungal spores are smaller and lighter than plant seeds.
  • The giant puffball mushroom bursts open and releases trillions of spores.
  • There are many types of asexual spores.
  • Other asexual spores originate in the fragmentation of a hypha to form single cells that are released as spores; some of these have a thick wall surrounding the fragment.
  • At this stage, spores are disseminated into the environment.

• Sporophytes and Gametophytes in Seedless Plants

  • Sporophytes (2n) undergo meiosis to produce spores that develop into gametophytes (1n) which undergo mitosis.
  • The term "sporangia" literally means "spore in a vessel": it is a reproductive sac that contains spores.
  • The spores are later released by the sporangia and disperse in the environment.
  • Seedless, non-vascular plants produce only one kind of spore and are called homosporous.
  • In contrast, heterosporous plants produce two morphologically different types of spores .

• Firmicutes

  • The name "endospore" is suggestive of a spore or seed-like form (endo means within), but it is not a true spore (i.e. not an offspring).
  • The cortex lies beneath the spore coat and consists of peptidoglycan.
  • The core contains the spore chromosomal DNA which is encased in chromatin-like proteins known as SASPs (small acid-soluble spore proteins), that protect the spore DNA from UV radiation and heat.
  • The DNA is replicated and a membrane wall, known as a spore septum, begins to form between it and the rest of the cell.
  • The oval, unstained structures are spores.

• Liverworts and Hornworts

  • The spore-producing cells undergo meiosis to form spores, which disperse (with the help of elaters), giving rise to new gametophytes.
  • The haploid spores germinate and produce the next generation of gametophytes .
  • Spores are released from sporophytes and form the gametophyte.
  • This sporophyte disperses spores with the help of elaters; the process begins again.
  • Liverworts also disperse their spores with the help of elaters, while hornworts utilize pseudoelaters to aid in spore dispersal.

• Life Cycles of Sexually Reproducing Organisms

  • The zygote immediately undergoes meiosis to form four haploid cells called spores.
  • The spores can remain dormant for various time periods.
  • The spores will subsequently develop into the gametophytes .
  • The zygote undergoes meiosis to produce haploid spores.
  • Each spore gives rise to a multicellular haploid organism by mitosis.

• Anthrax

  • Anthrax commonly infects wild and domesticated herbivorous mammals that ingest or inhale the spores while grazing.
  • Humans become infected through contact with the anthrax spores from infected animals.
  • By inhaling contaminated air containing anthrax spores.
  • By handling infected animals and/or animal products, antrax spores can enter through cuts in the skin.
  • By eating undercooked meat containing anthrax spores.

• Protist Life Cycles and Habitats

  • Meiosis produces haploid spores within the sporangia.
  • Spores disseminate through the air or water to potentially land in more favorable environments.
  • Cells atop the stalk form an asexual fruiting body that contains haploid spores.
  • As with plasmodial slime molds, the spores are disseminated and can germinate if they land in a moist environment.
  • The sporangium forms haploid spores through meiosis, after which the spores disseminate, germinate, and begin the life cycle anew.

• Zygomycota: The Conjugated Fungi

  • The black tips of bread mold, Rhizopus stolonifer, are the swollen sporangia packed with black spores .
  • When spores land on a suitable substrate, they germinate and produce a new mycelium.
  • When the zygospore germinates, it undergoes meiosis and produces haploid spores, which will, in turn, grow into a new organism.
  • The (b) tips of bread mold are the spore-containing sporangia.

• Seedless Vascular Plants

  • Seedless vascular plants, which reproduce and spread through spores, are plants that contain vascular tissue, but do not flower or seed.
  • In seedless vascular plants, such as ferns and horsetails, the plants reproduce using haploid, unicellular spores instead of seeds.
  • The spores are very lightweight (unlike many seeds), which allows for their easy dispersion in the wind and for the plants to spread to new habitats.

• High Pressure

  • The frist reports showed that bacterial spores were not always inactivated by pressure, while vegetative bacteria were usually killed.
  • Around 1970, researchers renewed their efforts in studying bacterial spores after it was discovered that using moderate pressures was more effective than using higher pressures.
  • These spores, which caused a lack of preservation in the earlier experiments, were inactivated faster by moderate pressure, but in a manner different from what occurred with vegetative microbes.
  • When subjected to moderate pressures, bacterial spores germinate, and the resulting spores are easily killed using pressure, heat, or ionizing radiation.